AIDS-Related Bronchogenic Carcinoma.Fact or Fiction: DeliberationA potential problem with the conclusions of these later studies may simply be related to their timing relative to the onset and management of the AIDS epidemic. These later studies, especially that of Biggar et al and Chan et al, were performed early in the AIDS epidemic, when most infected patients rapidly died of OIs. Our study and conclusion are conducted later in the AIDS epidemic, at a time when these previously life-threatening OIs are better managed. Infected patients now live longer, allowing for the development and recognition of these previously unrecognized neoplasms.
The earliest study with the strongest evidence that the frequency of lung cancer was increased in HIV-AIDS patients was by Braun et al. They suggested a 14-fold increased incidence of lung cancer in these patients. Sridhar et al reported a series of 19 HIV-positive patients with concomitant lung carcinoma. Prior to our report, Fishman et al had the largest reported series with 30 HIV-positive patients diagnosed as having primary lung cancer. In 1993, Cotie et al reviewed the cancer status of 83,434 people with AIDS from corresponding cancer registries. They concluded that both the prevalence and incidence were increasing for Hodgkin’s lymphoma, leukemia, and lung cancer in the HIV-AIDS patient population. Similar to our study, Barchielli et al linked the AIDS registry with the cancer registry in Florence, Italy, during 1985 to 1990. Although their study involved a small population, they concluded that the incidence of lung cancer was 95 times greater than the expected incidence of that in the general population in the same area.
Despite such reports, many investigators, ourselves included, believed there was insufficient epidemiologic data to link HIV-AIDS with primary lung cancer. Our population-based study provided sufficient numbers of lung cancer cases to statistically confirm an association between these two disease processes. Like Barchielli et al, we successfully linked two independent state databases, identified an HIV-AIDS cohort, and determined a statistically increased association of lung neoplasms in these patients. Not unexpectedly, sarcoma, primarily Kaposi’s, was the most frequently observed cancer. Utilizing the SEER total lung neoplasm incidence rate, we expected 5.6 total lung neoplasms (eg, sarcomas, carcinomas), but observed 76 cases. This represents a 13.6-fold increased incidence. Contrary to many other already addressed reports, the incidence of primary pulmonary carcinomas (eg, bronchogenic carcinomas) was also statistically increased in the HIV-AIDS cohort. The SIR of 6.5 for this group of lung cancers indicates a 6.5-fold increased incidence of primary lung cancer among the HIV-AIDS population. Additionally, the average delay of 18 months in reporting a case of lung cancer to the CRD makes it likely that not all lung carcinomas within the HIV-AIDS cohort have been identified. Thus, the SIR may represent an underestimate of the actual magnitude. Furthermore, the HIV status of many lung cancer patients outside the established cohort was unknown. Theoretically, some of these patients may be HIV positive, thus increasing the SIR even further.